Under constant illumination, single quantum dot is blinking, or fluorescence intermittency. This would greatly limit the application of using single quantum in particle tracking, as well as in lasing technology. In this research, we developed a theoretical model in which by studying the interaction between photons and single quantum dot (QD), we were able to explain almost all the characteristics of blinking, including under what condition non-blinking occurs, what results in grey state, as well as the power-law behavior.